Pins for mine and tunnel roofs and other structures

ABSTRACT

Pins adapted to be driven into a structure such as a mine or tunnel roof without the necessity for the prior formation of pin receiving openings in the structure. The pins each comprise an elongated shank having a leading end for providing a pin receiving opening in the structure during the driving of the pin thereinto, the leading end being blunt to prevent deviation of the pin from a desired path during its said driving, and the shank at such leading end including an enlarged leading end portion of greater peripheral dimension than a thereafter following portion of the shank to provide an opening in the structure larger than such thereafter following shank portion.

United States Patent [1 1 Banerjee et al.

[4 1 Sept. 3, 1974 PINS FOR MINE AND TUNNEL ROOF S AND OTHER STRUCTURES [73] Assignee: Lee-Norse Company, Charleroi, Pa.

[22] Filed: Apr. 16, 1973 [2]] Appl. No.: 351,575

6/1900 Great Britain .1 85/30 Primary Examiner-Ramon S. Britts Attorney, Agent, or Firm-Robert -R. Paquin [5 7 ABSTRACT Pins adapted to be driven into a structure such as a mine or tunnel roof without the necessity for the prior formation of pin receiving openings in the structure. The pins each comprise an elongated shank having a leading end for providing a pin receiving opening in the structure during the driving of the pin thereinto, the leading end being blunt to prevent deviation of the pin from a desired path during its said driving, and the shank at such leading end including an enlarged leading-end portion of greater peripheral dimension than a thereafter following portion of the shank to provide an opening in the structure larger than such thereafter following shank portion.

7 Claims, 4 Drawing Figures PINS FOR MINE AND TUNNEL ROOFS AND OTHER STRUCTURES The present invention relates to the provision of new and improved pins particularly adapted for insertion into a structure such as a mine or tunnel roof without the necessity for the prior formation of pin receiving openings in the structure.

U.S. Pat. No. 3,643,542, issued Feb. 22, 1972, discloses roof pins particularly adapted to form their ownopenings during insertion into a roof and, hence, avoiding the necessity that pin receiving openings be formed in the roof prior to the insertion of the pins. The pins of such patent are believed to represent a major advance in the field of roof support. However, as described in the patent, the forward or leading ends of the pins (that is, the ends of the pins acting to extend the lengths of the openings during the insertion of the pins) are of sharp pointed construction.

It is believed that such sharp, pointed configuration of the pin leading ends causes the pins to be undesireably susceptible to deviation from the desired straight path during insertion, due to the inherent tendency of such leading ends to follow any cracks or other weaknesses in the roof. The problems potentially arising as a result of any such deviation are compounded by the facts that (i) as the pins perform a safety function, any deviation that might detract from this function cannot be tolerated and (ii) as the pins are frequently several feet in length, substantial deviation from the desired straight path is at least theoretically possible.

An object of the present invention is to provide a new and improved pin of the type set forth which is particularly constructed and arranged to prevent the aforesaid deviation from occuring during the driving of the pin.

Another object is to provide a new and improved pin of the type set forth which is particularly constructed and arranged to include a blunt, rather than a sharp pointed, leading end.

Another object is to provide a new and improved pin of the type set forth which is particularly adapted to safely and efficiently retain a roof of a mine or tunnel.

Another object is to provide a new and improved pin of the type set forth which, although particularly adapted for mine or tunnel roof support, is readily employable for use in other structures.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein, as will be understood, the preferred forms of the invention have been given by way of iblustration only.

In accordance with the invention, a pin adapted to be driven into a structure such as a mine or tunnel roof, may comprise an elongated shank having a leading end for providing a pin receiving opening in the structure during the driving of the pin into the structure, such leading end being blunt to prevent deviation of the pin from a desired path during the driving of the pin into the structure, and the shank at such leading end including an enlarged leading end portion of greater peripheral dimension than a thereafter following portion of the shank to provide an opening in the structure larger than the thereafter following shank portion.

Referring to the drawings:

FIG. 1 is a side view of a mine or tunnel roof pin constructed in accordance with the present invention;

FIG. 2 is a view of the forward or leading end of the pin shown in FIG. 1;

FIG. 3 is a side view of another mine or tunnel roof pin constructed in accordance with the invention;

FIG. 4 is a view of the forward or leading end of the pin shown in FIG. 3.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts through the several views, FIGS. 1 and 2 illustrate a mine or tunnel roof pin, designated generally as 10, which comprises an elongated shank 12 having a forward or leading end 14 and a rearward or trailing end 16. The shank 12 may be, for example, of about 1 to 6 feet in axial dimension or length; and, although the shank 12 of the illustrated pin 10 is of circular crosssection, it will be understood that other suitable crosssections could be alternately employed.

The leading end 14 is the end of the pin 10 acting to form the longitudinal extension of the pin receiving opening during the driven insertion of the pin 10 into a mine or tunnel roof and is formed of blunt, flat, planar construction to prevent the beforedescribed deviation of the pin 10 from the desired straight path during the pin driven insertion. In addition, at such leading end 14, the shank 12 includes a substantially enlarged, leading end portion 18 of peripheral dimension P and transverse or cross-sectional area substantially greater than the adjacent, immediately thereafter following portion 20 of the shank 12, to provide an opening in the roof substantially larger than the shank portion 20. As illustrated, the shank l2 continuously tapers or gradually narrows in cross-section as it axially extends from its trailing end 16 to the enlarged leading end portion 18; and the shank trailing end 16 is of substantially the same cross-sectional area as the leadibg end portion 18. Hence, in the pin 10 the leading end portion 18 is of greater peripheral dimension and cross-sectional area than most, but not all, of the remainder of the length of the shank 12; however, as will be understood, in embodiments of the invention in which such remainder of the length of the shank 12 is of constant, uniform crosssection, the enlarged leading end portion 18 would be of peripheral dimension and cross-sectional area substantially greater than the entire remaining portion of the shank 12 to provide an opening in the mine roof substantially greater than said entire remaining portion of the shank.

The leading end portion 18 is of at least substantially constant or uniform cross-section throughout its length axially of the shank l2; and the leading end 14 extends at least substantially the full cross-sectional area of the leading end portion 18. The area of the annular peripheral surface of the leading end portion 18 is predetermined or preselected to control the force required for driving the pin 10 into the mine or tunnel roof; and the length L of the leading end portion 18 axially of the shank 12 is predetermined or pre-selected to control the force required for such driving of the pin 10, the leading end portion 18 being as illustrated only a minor portion of the length of the shank 12.

At its trailing end 16, the shank 12 carries an enlarged head 22 which, as illustrated, has an annular peripheral surface 24 continuously tapering from the shank trailing end 16 to the head end 26 of the pin 10, the head22 being maintained external to the mine or 3 tunnel roof after the pin insertion. lt will be understood that, although the peripheral surface 24 is preferably so tapered to reduce the probability of non-axial loading during driving of the pin 10,.such surface 24 could, if desired, be of other configuration. Also, as illustrated, the pin is of one-piece metal construction, thus forming the head 22 and shank 12 (including the leading end portion 18) unitary with one another, the metal construction of the leading end portion 18 preventing deformation of such portion 18 during driven insertion of the pin 10 into a roof. As will be readily appreciated, alternatively to this one-piece construction, the pin 10 could be formed of two-piece construction one piece comprising the head 22 and the there-adjacent section of the shank l2 and the other piece comprising the leading end portion 18 and the thereadjacent section or the remainder of the shank 12. In this event, provision would be made for suitably joining the shank sections of the two pieces of the pin 10 (for example, by mechanical couplings) after insertion of the pin portion including the leading end portion 18 into the roof. This two-piece or multiple-piece construction, as will be seen, enables the installation of a relatively long pin in the roof of a relatively low mine shaft or tunnel.

FIGS, 3 and 4, wherein parts similar to those of the beforedescribed pin 10 are designated by the corresponding reference numeral followed by the suffix a, illustrates a pin 10a in which the blunt leading end 14a of the enlarged leading end portion 18a includes an arcuate recess 28, Also, in the pin 10a the rearward end of the leading end portion 18a is joined to the forward end of the shank portion 20a by an annular, arcuate, outwardly extending portion 30 of the latter. Furthermore, as illustrated, the head 22a of the pin 10a is generally arcuate whereby the head end 26a of the pin 10a is arcuately contoured. The pin 10a is, however, in all other respects identical to the pin 10.

As will be understood the pin 10 could be provided with a head of construction similar to that of the head 22a; and the pin 100 could be provided with a head of construction similar to that of the head 22.

From the preceeding description it will be seen that the invention provides new and improved means for attaining all of the before described objects and advantages. It will moreover be understood that, although the pins provided by the invention are particularly adapted for use in a mine or tunnel roof, they are alternatively capable of employment in a mine or tunnel side wall or in construction work, or in other instances in which a pin is desired to be inserted in rock, concrete, masonry or other material.

It will be understood that, although only a few embodiments of the invention have been illustrated and hereinbefore specifically described, the invention is not limited merely to these few embodiments, but rather contemplates other embodiments and variations within the scope of the following claims.

We claim:

1. A pin adapted to be driven into a structure such as for example the roof of a mine or tunnel, comprising an elongated shank having a leading end for providing a pin receiving opening in the structure during the driving of the pin into the structure, said leading end being blunt to prevent deviation of the pin from a desired path during the driving of the pin into the structure,

said shank at said leading end including an enlarged leading end portion of substantially greater peripheral dimension than the thereafter following portion of said shank to provide an opening in the structure substantially larger than such thereafter following shank portion, said enlarged leading end portion being of at least generally uniform cross-section throughout its length axially of said shank and the area of said blunt leading end of said shank being at least generally the same as the cross-section of said enlarged leading end portion, said enlarged leading end portion, axially of said shank, being only a minor portion of the length of said shank, said enlarged leading end portion being of larger crosssection than at least the major portion of the remainder of the length of said shank, and the area of the peripheral surface of said enlarged leading end portion being predetermined to control the force required for driving the pin into the structure.

2. A pin according to claim 1, wherein said following portion of said shank includes an outwardly extending, arcuate peripheral surface rearwardly of said enlarged leading end portion.

3. A pin according to claim 1, wherein said leading end of said shank is at least generally flat.

4. A pin according to claim 1, wherein said leading end is recessed.

5. A pin according to claim 1, wherein said enlarged leading end portion is constructed of metal to prevent its deformation during the driving of the pin into the strucutre.

6. A pin according to claim 1, wherein said shank tapers in cross-section as it extends longitudinally towards its said leading end portion.

7. A pin according to claim 1, wherein said shank is provided with an enlarged head at its end opposite to said leading end. 

1. A pin adapted to be driven into a structure such as for example the roof of a mine or tunnel, comprising an elongated shank having a leading end for providing a pin receiving opening in the structure during the driving of the pin into the structure, said leading end being blunt to prevent deviation of the pin from a desired path during the driving of the pin into the structure, said shank at said leading end including an enlarged leading end portion of substantially greater peripheral dimension than the thereafter following portion of said shank to provide an opening in the structure substantially larger than such thereafter following shank portion, said enlarged leading end portion being of at least generally uniform cross-section throughout its length axially of said shank and the area of said blunt leading end of said shank being at least generally the same as the crOss-section of said enlarged leading end portion, said enlarged leading end portion, axially of said shank, being only a minor portion of the length of said shank, said enlarged leading end portion being of larger cross-section than at least the major portion of the remainder of the length of said shank, and the area of the peripheral surface of said enlarged leading end portion being predetermined to control the force required for driving the pin into the structure.
 2. A pin according to claim 1, wherein said following portion of said shank includes an outwardly extending, arcuate peripheral surface rearwardly of said enlarged leading end portion.
 3. A pin according to claim 1, wherein said leading end of said shank is at least generally flat.
 4. A pin according to claim 1, wherein said leading end is recessed.
 5. A pin according to claim 1, wherein said enlarged leading end portion is constructed of metal to prevent its deformation during the driving of the pin into the strucutre.
 6. A pin according to claim 1, wherein said shank tapers in cross-section as it extends longitudinally towards its said leading end portion.
 7. A pin according to claim 1, wherein said shank is provided with an enlarged head at its end opposite to said leading end. 